This application is related to and incorporates herein by reference Japanese Patent Applications No. 2002-218050 filed on Jul. 26, 2002, No. 2002-332450 filed on Nov. 15, 2002 and No. 2003-123621 filed on Apr. 28, 2003.
The present invention relates to a fuel supply apparatus, which resiliently presses a fuel injector to the cylinder head of an internal combustion engine.
Various fuel supply apparatuses are provided for injecting fuel transferred by a fuel transfer pipe into a cylinder of an internal combustion engine by a fuel injection device (injector). In some fuel supply apparatuses, one end of the injector on a side of a fuel injection port and the other end thereof on a side of a fuel flow inlet are respectively inserted in to a cylinder head and the fuel transfer pipe of the engine.
For example, according to an apparatus disclosed in JP-A-11-287168, a pressing member comprising a leaf spring is fixed to a cylinder head along with a stay provided at a fuel transfer pipe and an injector is pressed to a cylinder head by the pressing member.
According to this apparatus, between the fuel transfer pipe and the cylinder head, the pressing member is fixed to the cylinder head by a bolt. Therefore, when a fuel supply apparatus is integrated to inside of a V-bank of the cylinder head as shown, a space cannot sufficiently be ensured at a surrounding of a bolt fixing portion. In this case, it is difficult to fasten the bolt. Therefore, cost required for integration is increased and the magnitude of the axial force of the bolt cannot be achieved as expected. Particularly, since a press force for pressing the injector is obtained by resiliently deforming the pressing member comprising the leaf spring by the axial force of the bolt, a reduction in the axial force leads to a reduction in the pressing force. In the case of the leaf spring having a short free length, the spring constant must be set to be large in order to ensure the press force. Therefore, the press force is considerably reduced even by a slight reduction in the axial force.
Further, according to another apparatus shown in FIG. 16, a cylinder head 100 is fixed with a clamp member 102 and an injector 104 is pressed to the cylinder head 100 by the clamp member 102.
According to this apparatus, a middle portion 102b of the clamp member 102 is fixed to the cylinder head 100 by a bolt in a state of bringing one end 102a of the clamp member 102 into contact with the cylinder head 100 and the other end 102c of the clamp member 102 is engaged with an injector 104. Thereby, a lever comprising the one end 102a, the middle portion 102b and the other end 102c of the clamp member 102 respectively functions as a fulcrum. The injector 104 is pressed by the end 102c of the clamp member 102. The clamp member 102 utilized as the lever in this way needs to be highly rigid and therefore, the clamp member 102 becomes expensive.
Further, in order to fix the injector 104 to be durable against high combustion pressure in the engine, the distance between the end 102a and the middle portion 102b of the clamp member 102 needs to be long based on a lever ratio. Therefore, a large space needs to be ensured for arranging the clamp member 102 to deviate from a center axis of the injector 104 to one side in a diametric direction and depending on a shape of the cylinder head 100, arranging the clamp member 102 may become difficult.
It is an object of the invention to provide a fuel supply apparatus reducing cost required for integrating to a cylinder head of an engine.
It is another object of the invention to provide a fuel supply apparatus capable of easily and solidly integrating to a cylinder head of an engine.
It is a further object of the invention to provide an integrating part preferable for easily and solidly integrating a fuel supply apparatus to a cylinder head of an engine.
It is a still further object of the invention to provide a fuel supply apparatus requiring a small space for integrating to a cylinder head of an engine.
According to the first aspect of the present invention, a fuel supply apparatus has a fuel injection device, a fuel transfer pipe, a restricting member for restricting the fuel transfer pipe and a cylinder head from being separated from each other, and a pressing member interposed between the fuel transfer pipe and the fuel injection device. The pressing member receives a restricting force of the restricting member for pressing the fuel transfer pipe to a side opposing the cylinder head and pressing the fuel injection device to a side of the cylinder head by a reaction force against the restricting force.
According to the second aspect of the present invention, a fuel supply apparatus has a fuel injection device and a resilient integrating member for integrating the fuel injection device to a cylinder head. The integrating member includes a first pressing portion and a second pressing portion. The first pressing portion is fixed to the cylinder head for pressing the second pressing portion by being deformed resiliently. The second pressing portion is arranged between an insertion portion of the fuel injection device inserted in the insertion port and the insertion portion for pressing a projection projected from the insertion portion to an outer side in a diametric direction to a depth side of the insertion port by receiving a pressing force of the first pressing portion.
According to the third aspect of the present invention, a fuel supply apparatus has a fuel injection device and a resilient integrating member for integrating the fuel injection device to a cylinder head. The cylinder head has an insertion port as a locking portion by an inner wall thereof. The integrating member is locked by the locking portion to receive a reaction force and presses the fuel injection device to a depth side of the insertion port by the reaction force.